1. Field of the Invention
The present invention relates generally to industrial signaling devices for indicating the operating status of machinery or processes and, more particularly, to such signaling devices that are elevated in order to enhance their visibility.
2. Description of Related Art
Elevated industrial signaling devices are well-known in factory-type environments where numerous industrial machines are present. Generally, such industrial signaling devices are mounted on a pole so they are high above each machine and clearly visible from a distance. Each device typically has a plurality of modules that emit differently colored light for visually signaling the operating status of each machine.
In a typical signaling device, each of the lights is responsive to an operating status of the machine to which the device is connected. For example, a typical device has lights of various colors such as, blue, red, amber and green. Each of the these differing colors is contained in a discrete module. The differing colors of the lights correspond to various operating stages of the machine. For example, a blue light may indicate the machine is running correctly, an amber light may indicate that the machine is in need of service and a red light may indicate that the machine has ceased operating. The colors of the lights are very important because even at a distance an illuminated light of one color is immediately distinguishable from the other lights of different colors.
U.S. Pat. No. 5,103,215 to James et. al discloses a signaling light made from a plurality of differently colored vertically stacked modules with incandescent lights. The cover lens of each module may be removed separately and the bulbs in each module may be replaced without having to disassemble the entire piece.
U.S. Pat. No. 5,769,532 to Sasaki discloses a LED signaling light made from a plurality of differently colored vertically stacked modules. Each module contains a portion bulged outwardly, which is coated with a reflective material. The LEDs are arranged in rows so that their emitted light is reflected off the reflecting surface and projected into the environment surrounding the module.
U.S. Pat. No. 5,929,788 to Vukosic discloses a LED signaling device where clusters of LEDs arranged in rings are mounted on a circuit board and emit light on to a conical reflective surface. The conical reflective surface is outwardly flaring. In order to change to color of the emitted light different colored covers must be manually changed.
Elevated signaling devices are particularly effective in environments where the level of background noise is very high and there is a danger that an audible alarm will not be heard. Furthermore, the elevated signaling devices can distinguish between various malfunctioning conditions by relating different conditions to different colors of lights or to different frequencies of flashing lights. In a crowded factory, a system of elevated signaling devices enables maintenance people to quickly locate and identify specific problems in a large number of operating machines. Such a system is extremely effective and efficient because it enables a single individual to monitor a large number of machines from a distance where the operating status of all the machines can be simultaneously observed.
While these elevated signaling devices have proven to be very effective, they also have various disadvantages. Typical devices are made with a plurality of modules, where each module illuminates a different colored light. A design of one color per single module has numerous disadvantages.
One such disadvantage is when the manufacturing operation takes place in a clean room, such as in the manufacture of semiconductor devices. In order to have better environmental control, it is desirable to reduce the volume of the clean room as much as possible. Industrial signaling devices that employ multiple modules are often too large to be used in clean rooms that have reduced height. Also, multiple module lights have numerous interfaces between the lens of the light and the housing of the electrical components. Each connection interface is a weak spot where water, liquid, dust, corrosive materials, etc. can enter the light and ruin electronic components. Moreover, the manufacture of such multiple module lights is wasteful, and sometimes assembly of the multiple modules is required by the end user. Multiple modules require greater storage space and can be more expensive to handle and ship. They are also more cumbersome to install or service and this can be difficult when the multiple modules are at the end of a pole ten feet or more above a factory floor. Usually, a maintenance person climbs a ladder in order to reach the signaling device.
Set forth is a brief summary of the invention in order to solve the foregoing problems and achieve the foregoing and other benefits and advantages in accordance with the purposes and the present invention as embodied and broadly described herein.
The present invention provides an industrial signaling device having a light source within a single module, whereby the light source and emits a light of two or more colors that can be separately activated. In an embodiment of the present invention the module has a microprocessor that interprets incoming information and separately activates each differently colored light source. In another embodiment, the emission of the light is controlled by an external programmable logic controller and the module optionally contains a microprocessor. Light sources contemplated for use in this invention include LEDs, ionizable gas or a flourescent light. The present invention may include a reflective material mounted to reflect light out of the module. In another embodiment lens cover of the module is made from a polycarbonate material.